Integrated semiconductor devices that include one or more photonic devices, such as photodetectors, modulators, optical switches, and the like, require a mechanism to couple optical signals between the optical fibers used to communicate optical signals to and from the semiconductor device and the silicon based waveguides that are within the semiconductor devices and used to deliver the optical signals to the photonic devices within the integrated semiconductor devices. Coupling from an optical fiber to a photonic device with input and output waveguides often suffers from loss due to index and mode-profile mismatches.
Polymer couplers are one technique used to minimize losses in coupling between an optical fiber and input and output waveguides of a photonic device embedded in an integrated semiconductor device. Polymer couplers have been demonstrated to provide effective matching and to result in low coupling losses. Optoelectronic circuits, however, are often fabricated onto integrated semiconductor devices using conventional semiconductor fabrication techniques, such as techniques for fabricating CMOS circuits. Fabricating polymer couplers for use in applications wherein the photonic devices need to be encapsulated and annealed, as in many CMOS-compatible processes, presents fabrication difficulties that increases the complexity of device fabrication.
Therefore a need exists to overcome the problems with the prior art as discussed above.